Why I sometimes reject patches for my own software
I recently read Drew Crawford's Conduct unbecoming of a hacker (via), which argues that you should basically always accept other people's patches for your software unless they are clearly broken. Lest we bristle at this, he gives the example of Firefox and illustrates how many patches it accepts. On the whole I sympathize with this view, and I've even had some pragmatic experience with it; a patch to mxiostat that I wasn't very enthusiastic about initially has actually become something I use routinely. But despite this there are certain sorts of patches I will reject basically out of hand. Put simply they're patches that I think will make the program worse for me, no matter how much they might help the author of the patch (or other people).
This is selfish behavior on my part, but so far all of my public software is things that I'm ultimately developing for myself first. It's nice if other people use my programs too but I don't expect any of them to get popular enough that other people's usage is going to be my major motivation for maintaining and developing them. So my priorities come first and the furthest I'm willing to go is that I'll accept patches that don't get in the way of my usage.
(Drew Crawford's article has sort of convinced me that I should be more liberal about accepting patches in general; he makes a convincing case for 'accept now, bikeshed later'. So far this is mostly a theoretical issue for my stuff.)
By the way, this would obviously be different if I was developing things with the explicit goal of having them used by other people. In that case I should (and hopefully would) suck it up and put the patch in unless I had strong indications that it would make the program worse for a bunch of people instead of just me. Maybe someday I'll write something like that, but so far it's not the case.